Pityriasis rosea is a common skin rash. It occurs most often in children and young adults. The rash is scaly and reddish-pink. It may first appear on the back, stomach, or chest. The rash can then spread to the neck, arms, and legs.

The rash may last for several months. It will usually go away on its own. Talk to your doctor if you have a widespread rash.

The cause of pityriasis rosea is unknown. It may be caused by viruses or a certain medicine, such as antibiotics or heart medications.